Modern American immigration policy is rooted in the Immigration and Nationality Act of 1965, which dramatically changed the then existing system. The 1965 Act, also known as the Hart-Cellar Act after the bill’s sponsors, fundamentally changed the manner in which immigrants were deemed eligible for admission to the United States. Prior to its enactment, American immigration policy was based on race and ethnicity, favoring immigration from northern and western Europe to the exclusion of eastern and southern Europe, Asia, Africa, and the Americas.
The previous system, originating under the Immigration and Nationality Act of 1924 and revised under the Immigration and Nationality Act of 1952, relied upon quotas for admission based on an immigrant’s nation of origin. The 1924 Act was rooted in feelings of xenophobia and isolationism, and intended to keep the United States population as homogeneous as possible. The legislature relied upon eugenics as justification for nearly eliminating catholic and Jewish immigration, as well as a complete ban on Chinese and Japanese immigrants, in order to prevent the spread of “feeblemindedness in American society.”
The 1924 Act dramatically slashed immigration by over 50% in one year. The basic formula limited the number of immigrants from a particular country 2 percent of the foreign-born population of that country living in the United States as of the 1890 census. The existing composition of the American foreign born population was heavily skewed towards northern and western European countries of origin, which were perceived as the most favorable countries from which to receive immigrants.